Certain cabling machines, notably cabling machines as disclosed in U.S. Pat. No. 4,932,198, filed Apr. 26, 1989 and which is incorporated herein by reference in its entirety, are provided with a plurality of cabling stations. Each cabling station has a bobbin creel assembly, with each bobbin creel assembly in turn having a creel support arm supporting the bobbin creel and associated spindles upon which cord or thread bobbins are mounted. A thread-combining machine that is part of a cabling machine is located beneath the bobbin creel, and receives a first cord or thread from a bobbin on the bobbin creel and a second cord or thread from a second bobbin located beneath the thread-combining machine. Because of the relatively high weight of bobbins filled with cord, the upper bobbin creel assemblies are designed with bobbin creel support arms or members pivotally mounted and enabled to be pulled downward to a location approximately chest high so as to minimize a height to which the loaded bobbins must be lifted by workers to be mounted on the spindles supported by the bobbin creel. As the weight of the bobbin creel assembly and bobbins loaded with cord is substantial, a gas strut similar to gas struts found on a rear hatch of hatchback vehicles is mounted to the bobbin creel assembly to apply a bias between members that support the bobbin creel assembly in such a way that assists in lifting the bobbin creel assembly with a loaded bobbin back into its upright operating position. An automatic latch is also provided on the bobbin creel support arms or support members to automatically latch the bobbin creel against the bias applied by the gas strut in its lowered position so that an empty or near-empty bobbin may be replaced without having to hold the bobbin creel assembly down against the bias of the gas strut.
As shown in FIG. 1a, an illustration of such a prior art automatic latch, latch member 1 is mounted to the creel support arm and latch member 2 is mounted to a support arm that causes latch member 2 to slide inwardly within a channel 3 when the bobbin creel is pulled downward to replace a bobbin. An arm 4 having a downwardly extending pin 5 on an end thereof is mounted so as to be stiffly movable in directions indicated by arrows. Within member 2, a combination of lands 7 directs pin 5 into slot A, as indicated by an arrow, when member 1 is pushed into member 2. This action occurs when the bobbin creel is pulled downward, the downward motion terminating when pin 5 bottoms out in slot A. When the bobbin creel is released, the gas strut biases the bobbin creel upward, moving pin 5 out of slot A and against a land 9, which guides pin 5 into a capture region as indicated by the dashed line showing of pin 5. After a full bobbin is loaded onto the bobbin creel, the bobbin creel is again pulled downward, causing pin 5 to ride against land 11 into slot 13, again terminating the downward motion of the bobbin creel. When such downward motion is terminated, the bobbin creel is released and pushed upward by combination of the bias of the gas strut and force applied by a worker, causing pin 5 to move out of slot 13 in the direction as indicated by the arrow against land 15, which serves to center pin 5 as shown along a longitudinal axis of member 1 in preparation for the next downward cycle of the bobbin creel.
While this latch functions for its intended purpose, i.e. to automatically lock the bobbin creel in its lowered position and unlock the creel responsive to weight of a full bobbin, it is expensive to manufacture and contains relatively delicate parts that are prone to breakage and bending, particularly when the bobbin creel is lowered with excessive force. In addition, this latching device is prone to jamming, particularly after parts become worn. When this occurs, it is a natural inclination to bang the bobbin creel alternately up and down in an effort to free the latch, this effort usually breaking parts in the latch. As such, this latch must be frequently replaced.
In accordance with the foregoing, a need exists for an automatic latching device for a bobbin creel assembly or other assembly, and which is sturdy of construction and not prone to breakage, is less expensive to manufacture or fabricate and which functions in a simpler and more reliable manner.